A note on the deformation of 1D ferromagnetic domain walls due to double exchange interaction with a free electron gas

Abstract: Using an S-matrix formulation we evaluate the thermodynamic potential and conductance of a Bloch or N\'eel magnetic wall interacting with a one dimensional free electron gas via a double exchange interaction. The minimization of the elastic magnetic energy plus electronic thermodynamic potential indicates that for chemical potential larger than the magnetic interaction the domain wall is generally deformed to a thin wall, while for magnetic interaction larger than the chemical potential tends towards wide walls. In contrast, for a double wall configuration the deformation is always towards wide walls. For the single as well as the double magnetic wall configurations the conductance monotonically decreases with decreasing wall width. The thermodynamic potential and conductance of Bloch and N\'eel magnetic domain walls are identical within this prototype model.